Evaluation of vertebrobasilar arterial blood flow during HeartMate3 support via computational fluid dynamics analyses

Continuous Flow Left Ventricular Assist Devices (CF-LVADs) are used to support the failing left ventricle in patients with end-stage heart failure. CF-LVADs unload the left ventricle continuously and generate non-physiological blood flow in the cardiovascular system, which may cause major complications, including neurological events such as haemorrhagic strokes. Therefore, quantifying the blood velocities and analysing altered blood flow in the cerebral circulation during CF-LVAD support will help to understand the effects of mechanical circulatory support on cerebral blood flow. The aim of this study is to evaluate blood flow in the vertebrobasilar arteries in a healthy condition and heart failure with reduced ejection fraction and during HeartMate 3 CF-LVAD support. Blood velocities and wall shear stresses in the vertebrobasilar arteries were evaluated using Computational Fluid Dynamics analyses for a healthy condition, heart failure with reduced ejection fraction and during HeartMate 3 support. Simulation results showed that time-averaged wall shear stress and relative residence time decrease in the vertebrobasilar arteries in heart failure. HeartMate 3 support provides comparable cerebral arterial average blood flow rates, pressures, time-averaged wall shear stresses and relative residence times to healthy conditions, although wall shear stresses and blood velocities are altered.